KNX Metering is smart

The rising cost of energy, the need for commercial viability and the protection of the climate call for more transparency in energy consumption. The general practice of annual energy bills does not help in this matter. Changes are on the horizon only with respect to the supply of electricity. By using intelligent energy meters, electricity consumers could view their consumption as it happens and would be in a better position to control it. With KNX, more detailed choices regarding the responsible use of energy are possible already now, not only for electricity but also for heat, water and fossil fuels such as oil and gas. Numerous KNX components are already available on the market.

Transparency

One key element for achieving more selective energy consumption patterns
by consumers in buildings is to make it possible for them to monitor their
on-going energy consumption as directly as possible. For a long time now we
have had fuel consumption indicators in cars that show our current consumption:
when we press the accelerator impulsively or drive with ‘a heavy foot’, we can
see immediately how our fuel consumption jumps up or stays high. It could be
the same in buildings. But unfortunately, only very few are as yet equipped
with such metering devices. This method, also called ‘smart metering’, provides
intelligent metering and display of the energy consumed. I can only make more
economic choices with my use of energy, such as turning off appliances or
shifting uses to cheaper tariff time zones, when I know where and what for I am
currently using energy.

Legal requirements

When consumers are able to see their consumption patterns, for example, for electricity in residential buildings, commercial units or in industrial premises, this simple fact can heighten their awareness of the energy consumed. People who are confronted with their energy costs while consumption takes place can quickly take appropriate measures to reduce that consumption. For this reason, even policy makers are discussing the introduction of intelligent electricity meters (smart meters) for the sake of greater transparency in electricity consumption. Legal requirements stipulate that the utility company installs new energy meters at the customers’ premises, which carry out an interval-controlled energy consumption metering which is read either remotely or directly at the meter, and make the results available to customers in suitable ways. Possible options are to inform customers about their energy consumption via written notice, via internet access to the utility company, or directly. The advantage for customers is that they obtain information about their energy consumption patterns based on selectable intervals rather than having to wait for the annual energy bill and being informed about their estimated energy consumption costs by extrapolation from the previous year’s meter readings. However, this hoped-for advantage for customers is reduced by the fact that the legal requirement only stipulates energy readings for daily intervals and is also confined to the metering of electrical energy. The disadvantages are, firstly, that customers will not obtain much useful information from daily energy consumption curves and will not be able to draw any conclusions for the consumption patterns of individual appliances. Secondly, where electricity is not used for space heating, energy costs refer more to fuels such as gas, oil or district heating

A task for KNX

We also have to question the usefulness of customers being informed about their heating costs when they do not get any information about the temperature in their rooms, the ventilation status of their windows or the occupation status of the apartment/house. How useful is it for customers to be informed about the cost of electricity supply when they do not know the settings of their various appliances or whether rooms are occupied or not? Customers will be able to draw better conclusions about consumption patterns and potential savings or about optimising their usage patterns when they have information about the temperature in their rooms, the ventilation status of their windows and the occupation status. For this situation, KNX offers visualisation and automation solutions that can be combined with the metering of energy data. The result of this implementation is an active energy management, which can be used by customers to obtain information and, more importantly, will highlight any necessary changes of user patterns shown on the visual display.

Conclusion

In the concept for introducing Smart Metering the ROI (return on investment) or cost neutrality is of great importance. The investment is offset by increases in efficiency through on-line meter reading and billing and, particularly, by cost reductions in energy consumption. Any remaining ‘cost gaps’ can be closed by additional services. Possible options are continuous user information, monitoring devices, e.g. smoke detectors, glass breakage sensors, room heating controls, monitoring facilities for the vital functions of occupants etc. An important prerequisite for these services is the compatibility of the metering devices and instruments with the KNX world.